Load indicator for centrifugal separator



y 1 1962 w. c. SMITH ETAL 3,044,625

LOAD INDICATOR FOR CENTRIFUGAL SEPARATOR Filed Nov. 4, 1957 33 26 Fl G 3L as ,-' 37 INVENTORS.

38 I as WILLIAM c. SMITH 5 y K. HENNINGER A TORNEY 7 3,044,625 LOADINDICATOR FOR CENTRIFUGAL SEPARATOR William C. Smith, Moline, and ClydeK. Henmnger, Geneseo, Ill., assignors to Ametek, Inc., a corporation ofDelaware Filed Nov. 4, 1957, Ser. No. 694,241 3 Claims. (Cl. 210-86) Thepresent invention relates to centrifugal separators, and particularly toa new and improved load indicator for centrifugal separators. I

The operation of centrifugal separators often includes thecontrolledfeediug of a slurry or the like to the rotating basket of sucha separator. The duration of feeding is often controlled in the cyclicoperation of such separators by a timing device. In many instances, the

, solids concentration of the slurry may vary during the cyclicoperation of a separator'so that a greater volume of solids is fed tothe basket within a predetermined time preset on the timing device. Insuch instances, overloading of the basket may occur with the attendingdifiiculties of overloading the apparatus and/or the loss of such slurrythrough the discharge opening of the apparatus prior to its beingcentrifuged. 7

Many attempts have been made to provide load indi cators for centrifugalseparators with varying degrees of success. One drawback of knownindicators is the turbulence and splashing caused in the material .beingtreated when the indicating elements contact the material. This actionproduces excessive strains and stresses in the indicator which operateto reduce its efficiency and life. Additionally, it is often'desirableto avoid excessive turbulence of the material being treated,particularly where undesirable fumes and mist might be produced whichupon escaping would constitute a hazard.

The principal object of this invention is to provide a load indicator ofsimple construction which will be effective to indicate the load of acentrifugal separator with: out disturbing the condition of the materialbeing treated, while still being capable of efficient operation and longlife. V

Another object of this invention is to provide a load indicator that canbe adjusted for various densities of material to be treated so that asubstantially uniform action of the indicator will occur regardless ofthe material being treated.

Another object of the invention is to provide a load indicator'thatcanbe preset for a desired response to suit particular operatingconditions. A

Another object of this invention is to provide a load indicator thatwill cause a centrifugal separator to which it is applied to process amaximum load of solids regardless of the solids concentration in the,slurry, so long as the feed timer is set to allow the collection of afull basket of solids when the slurry contains the minimum percentage ofsolids-concentration. v

'One aspect of the invention may be to provide an oscillatable shaftthat vertically extends into the basket of V a centrifugal separator onwhich may be fixedly mounted of the oscillatable shaft may be providedwith a rigid arm that may cooperate with a spring loaded microswitch orthe like that may be normally closed, and adapt-ed to be opened when theoscillatable shaft is turned Unit States atent f I Patented July 17,1962 by coaction between the thin blades and the material being treated.The micro-switch maybe connected into the timing circuit including thefeed valve, so that should the load within the rotating basket becomeexcessive during the preset timed interval on the timer, the feed valvecan be closed off until the load is normal, at which time the feed valvemay be reopened to continue the feed.

The above, other objects and novel features of the invention willbecome-apparent from the following specification and accompanyingdrawing which is merely exemplary.

In the drawing:

FIGURE 1 is a partial elevational view of a centrifugal separator towhich the principles of the invention have been applied;

FIG. 2 is a top plan view of the load indicator and looking in thedirection of the arrows along line 2 -2 of FIG. 1; and

FIG. 3 is an enlarged sectional elevational view taken substantiallyalong line 33 of FIG. 1.

Referring to the drawing, and particularly to FIG. 1, the principles ofthe invention are shown as applied to a centrifugal separator of thebottom discharge type, although they may with equal facility be appliedto any type of centrifugal separator. The separator shown may include abed plate 10 on which are mounted three equally spaced pedestals 11(only two being shown) that include mechanism for supporting a housing12 for limited oscillatable movement. The housing 12 may have fixed toits sides brackets 13 that extend into the pedestals 11 for cooperationwith supporting mechanism therein.

A basket 14 having a top opening 14' may be located within the housing12 and may comprise a perforated cylindrical member for passing liquidtherethrough, which liquid is collected within an annular chamber withinthe housing 12. The bottom of the basket 14 may be provided withdischarge passages for gravitating solids collected within the basketincident to the centrifuging of the material being treated. v

The basket may be provided with a multiple V-belt sheave (not shown) ona vertically disposed spindle to which the basket 14 may be fixed.\l-belts 15 may connect the sheave on the basket spindle with anothersheave (not shown) on the axis of rotation of an hydraulic motor 16 thatis adapted to be operated at varying rates of speed for loading,separating and discharging material to be treated.

The top of the housing 12 may be provided with a top plate 17, and acover plate 18 of semicircular form, mounted on a hinge pin 19, maycover a correspondingly shaped opening the top plate 17 to provideaccess to the interior of the basket 14.

A feed pipe 20 may extend from the exterior of housing 12 through thetop plate 17 and open into the basket 14 along its vertical axis ofrevolution. The inner end of pipe 20 may extend through an opening 21within the top of a truncated, conical distributing member 22 that maybe fixed to the rotatable spindle that supports the basket 14 and,therefore, feed cone 22 rotates with the basket 14. The flow of materialto be treated through the pipe, 20 may be started or stopped by theoperation of a solenoid valve (not shown) which may be controlled by apreset timer (not shown).

A plate 23, having an opening 24 therein, may be fixed to the top plate17 in a manner such that opening 24 coincides with a similar opening 25within the top plate 17. A load indicator L may be mounted on plate 23and extend vertically into the basket 14 through its top opening 14.

Referring to FIG. 3, the load indicator L may include a tubular support26 that may be held in a predetermined vertical position by releasableclamping members 27 and 28. One of the members 27 or 28 may be fixed toplate 23, while the other may be unattached, but clamped around thetubular member 26 and held to the other member by bolts 29 and 30.

The tubular support 26 may be counterbored at each end to receivealigned bearing glands 31 and 32 which may be of any material such asbronze, babbitt, nylon or the like. A cylindrical shaft 33 may extendthrough the support 26 and be held in vertically adjustable position bya collar 34 fixed thereto and resting on the flange of gland 32.

The lower end of shaft 33 is reduced in diameter providing a shoulder35, and a plurality of thin blades 36 may be fixed to shaft 33 by a key37. Spacers 38 may be employed to separate the blades 36, and a washer39 may be removably fastened to the lower end of shaft 33 in a manner tohold the assembly of blades 36 and spacers 38 in proper relationship.The arcuate extent of the blades 36 may be varied, as may the verticalspacing and number thereof, to suit the operating conditions whichprevail.

A bracket 40 may be fixed to plate 23, and it may support a normallyclosed switch 41 of the so-called micro-switch variety. An operating arm42 having a roll 43 thereon may extend from switch 41 into the arcuatepath of movement of a lever 44 fixed to the collar 34 which, in turn, isfixed to the shaft 33. A collar 45, fixed to the stationary tubularsupport 26, may support spaced pins 46 and 47 defining the extent ofarcuate movement of the lever 44. Resilient means 41 may force the arm42 in a clockwise direction (FIG. 2), holding switch 41 closed and arm44 against stop 47. This is the condition before blades 36 contact thematerial in the basket.

The switch 41 may be wired in series into the timing circuit of thesolenoid valve that controls the feeding of material to be centrifugedthrough the feed pipe 20. With the apparatus in the condition shown inFIG. 1, the material fed through the pipe 20 is distributed through theopening 22 of the feed cone 22 by centrifugal force. It exits fromopening 22 in the form of a thin, circular sheet which is directedagainst the side walls of the rotating basket 14, where it movesupwardly and downwardly until an annular layer of the material to betreated covers the inner side wall surface of the perforated basket 14.This annular wall increases in thickness as more material is fed throughthe pipe 20. The timer for the solenoid valve is usually preset so thata known quantity of material for a given batch is treated. However,should the thickness of the annular layer of material on the inner wallof basket 14 increase at a too rapid rate so that the apparatus wouldtend to become overloaded, or fail to drain as fast as it is being fedthrough pipe 20, the inner peripheral surface of this rotating annularlayer of material will Wipe over the blades 36, causing the shaft 33 andarm 44 to move in a clockwise direction (FIG. 2) thereby moving arm 42in a counterclockwise direction, whereupon switch 41 is opened and thesolenoid valve for controlling the feed of material through the pipe 20is closed until such time as the inner peripheral surface of therotating material recedes from blades 36 when the switch willautomatically close, re-energizing the feed solenoid and continuing thefeed of the material through the pipe 2t).

Although the various features of the new and improved load indicatorhave been shown and described in detail to fully disclose one embodimentof the invention, it will be evident that numerous changes may be madein such details, and certain features may be used without others withoutdeparting from the principles of the invention.

What is claimed is:

1. In a centrifugal separator having a rotatable basket, means forfeeding material into said basket; means for rotating said basket assaid material is fed thereinto, whereby said material is rotated andforms an annular shell on the inside of said basket; a load indicatorextending into said basket, said indicator including a shaft; separatelyremovable oscillatable thin blades keyed to said shaft; spacers betweensaid blades for maintaining them in spaced planes normal to the innerperipheral surface of said shell of material; removable means at the oneend of said shaft for maintaining said blades and spacers on said shaft,whereby the number of blades may be varied to provide a predeterminedsensitivity of said indicator for materials having different densities;and means responsive to the engagement between said blades and saidshell for oscillating said blades for stopping the feeding of materialto said basket.

2. A load indicator for a centrifugal separator com prising incombination, a tubular support; aligned bearings within said tubularsupport; a shaft journaled in said bearings and extending beyond both ofsaid bearings; a plurality of separately removable thin blades keyed tothe one end of said shaft and extending radially therefrom in alignedrelation and in parallel spaced planes; separately removable spacersbetween said blades; removable means at the one end of said shaft for:maintaining said blades and spacers on said shaft, whereby the number ofblades may be varied to provide a predetermined sensitivity of saidindicator for materials having different densities; and a switchoperating arm fixed to the opposite end of said shaft.

3. Apparatus comprising in combination, a support; a tubular memberadjustably clamped to said support and extending through an openingtherein; aligned bearings within said tubular member; a shaft journaledin said bearings and extending beyond both of said bearings;

separately removable thin blades arranged in aligned relation keyed toone end of said shaft; separately removable spacers between said blades;removable means at the one end of said shaft for maintaining said bladesand spacers on said shaft, whereby the number of blades may be varied toprovide a predetermined sensitivity of said indicator for materialshaving different densities; an arm fixed to the other end of said shaft;and a switch mounted on said support and including an arm resilientlyurged into engagement with the arm on said shaft.

Steps Jan. 11, 1938 Hertrich May 3, 1955

